[quote=“Norx”]Numbers are different if the Total resistance is 1,5ohm.[/quote]Indeed but I measured mine and it’s 0.65 ohm…
I had to swap my home made power expander for a SSR because I didn’t check the resistance before connecting the bed and it blew one of the copper paths of the expander (acted like a fuse).

[quote=“raby”][quote=“Norx”]Numbers are different if the Total resistance is 1,5ohm.[/quote]Indeed but I measured mine and it’s 0.65 ohm…
I had to swap my home made power expander for a SSR because I didn’t check the resistance before connecting the bed and it blew one of the copper paths of the expander (acted like a fuse).[/quote]

That means if you are updating to heatbed you should not change to RSP-320 as in the Heatbed for dummies document but one with atlest 500-550w

@Norx:
Sorry to hear that the information in my document is not accurate. But since I know nothing about electronics, I used information from this forum. Somewhere is written that 2 nozzles takes about 120W and the 12V heatbed needs another 100W. Is the remaining 100V not enough for the rest of the printer needs?
I don’t understand…

[quote=“svdv”]
You mean if the bed is connected to the 12V pads, but the PSU is 15V, it takes still 345W?[/quote]Yes, the higher the voltage the more power it will drain (but it will heat a lot quicker too).

[quote]That means if you are updating to heatbed you should not change to RSP-320 as in the Heatbed for dummies document but one with atlest 500-550w

@Norx:
Sorry to hear that the information in my document is not accurate. But since I know nothing about electronics, I used information from this forum. Somewhere is written that 2 nozzles takes about 120W and the 12V heatbed needs another 100W. Is the remaining 100V not enough for the rest of the printer needs?
I don’t understand…[/quote]

Don’t be sorry @svdv , your effort in the document has helpt me alot, the latest information regarding W requirments is new to me aswell after reading hundres of threads before jumping on the installation. - Without the document (and Marlaks heatbed) I would still be bying Buildtak and not beeing able to print ABS and even having issues with the larger PLA prints. Now I manage to print on the whole buildplatform and still have an 90% successrate vs 30-40% before. Vertex with heatbed is doubling the value of the printer. Thank you.

Using orignal PSU for the vertex, and RSP-320 only for the heatbed seams to work. RSP-320 shuts itself of if it is overloaded so I dont belive there will be issues with it being a bit undersized, but for those using thinking about extending to a similar setup go for a larger PSU, >350w for 15V.

Have to say i am nervous to go on this adventure.
But looking at all the post and specially the fact that there is a dummy guide (thanks for that @svdv) gives me the good hope i can build it.
I did send you a email Marlark, i will wait on your response so i am sure i do it correctly with the paypall transfer.

A combination of many things. But the main reason is that i live in sweden and sweden is a expensive place if your going to send anything anywhere with anyone especualy as a private person. I wish it wasnt but i cant realy do much about that There is a cheeper way but it would require a lot more work to save a couple of Swedish crowns and to be honest it aint worth it sins i dont make anything by doing this. I have money put into this but when all of them are gone i will only have made a + on the 2 plates that i got for free from the supplier. If i where a company and had a agreement with the shipping company then it would be somewhat cheeper but i dont have that.